Rotary vane pump



March 17, 1953 J. s. wlLcox 2,631,544

ROTARY VANE PUMP Filed June 11, 1946 5 sheets-sheet 1 lie JNVENToR. Jef/N m1/44er h//z cal BY March 17, 1953 J. s. wlLcox Y 2,631,544

ROTARY VANE PUMP Filed June 11, 1946 5 Sheets-Sheet 2 March 17, 1953 J. s. wlLcox ROTARY VANE PUMP 5 Sheets-Sheet 3 Filed June 11, 1946 INVENTOR. c/OA/A/ Jwae h//Lwl BY f March 17, 1953 J. s. wlLcox 2,631,544

ROTARY VANE PUMP Filed June 1'1, 194e 5 sheets-sheet 4 t INVENTm Jox/N rfw h//L cox March 17,'1953 J.' s. wlLcox 2,631,544"

ROTARY VANE PUMP I Filed June 11, 194e ss'heqts-.sneers Patented Mar. 17, 1953 UNITED STATES er ROTARY VANE PUMP John Stewart Wilcox, Inglewood, Calif., assigner to Technical Instrument Laboratory, Inglewood, Calif., a copartnership Application June 11, 1946, Serial No. 676,035

2 Claims.

My invention relates to pumps of the vane type and more particularly to a pump of this type employing rollers as vane elements.

The pump of my invention includes many im provements over previous designs to render it more eicient and cheaper to manufacture. It includes the use of improved rollers, improved rotors, improved cavity forms, improved variable cavities, novel sealing means, improved flow control mechanisms, improved end plates and improved assembly construction. These improvements are combined in the pump which Will be described producing an overall improvement in pump performance as well as providing new pump design and constructions.

It is, therefore, an object of the invention to provide a vane-type pump, wherein the pump cavity is of a selected design for efficient and long lasting operation.

Another object of the invention is to provide a vane-type pump having a contact point between the rotor and casing formed of a separate plate that is formed in a true arc.

Still another object is to provide a roller-type vane pump having improved roller construction.

Still -another object of the invention is to provide a pump cavity of improved construction, which produces improved results as either a constant capacity or variable capacity pump.

A further object is to provide a vane pump with end plates which are automatically adjust- -able to bear against the rotor with a pressure proportional to the pressure developed Within the pump.

Another object of the invention is to provide a vane-type pump in which the entire pump assembly is secured together by a locking ring.

Fig. l is an elevation side View of the pump of my invention;

Fig. 2 is an elevation front view of the pump as indicated by the lines II-II of Fig. 1;

Fig. 3 is a partial vertical section through the pump of Fig. l as indicated by the line III-III yof Fig. 2;

Fig. 4 is a transverse section through the pump along the line IV-IV of Fig. 3;

Fig. 5 is a partial sectional View through the pump along the line V--V of Fig. 4;

Fig. 6 is a sectional view of the pump housing alone taken along the line VI-VI of Fig. 4;

Fig, 7 is a partial sectional view of the pump housing and the end plate assembly and is taken along the line VII- VII of Fig. 4;

Fig. 8 is an elevation view of the cavity ring of the pump also shown in Fig. 4; y

Fig. 9 is a sectional view of the cavity ring taken `along the line IX-IX of Fig. 8;

Fig. 19 is a perspective view of the spider insertable in the cavity ring for varying the capacity of the pump;

Fig. 11 is a perspective view of a stationary part of an end plate assembly of the pump;

Fig. 12 is a perspective view of the adjustable portion of the end plate assembly, adapted to be inserted in the part of Fig. 11 by rotation about a vertical axis of Fig. 13 is a view through the adjustable end plate portion of Fig. 12 taken along the line XIII-XIII of Fig 12;

Fig. 14 shows a modied form of roller for use in the invention lcomprising a metal rod coated with rubber-like material; n

Fig. 15 shows a second modication of roller for use in the invention, including articulated end pieces;

Fig. 16 shows a third modification of roller for employment in the invention consisting of vane elements drilled yto receive a roller that projects slightly from the outer surface of the vane;

Fig. 17 is an application of the pump of the invention in a uid mixing arrangement wherein variable proportions of the mixed fluids may' be obtained;

Fig. 18 is a schematic illustration of a pump housing and cavity ring that are employed when a constant direction of iiow of output is desired, regardless of the direction of rotation of the rotor of the pump;

Fig. 19 is a perspective view of one of the arc blocks employed to dene the pump cavity;

Fig. 20 is a detail sectional view of a portion of the spider shown in Fig. 10 taken along the plane XX-XX of Fig. 10;

Fig. 21 is a perspective view partly in section of a modied form of pump roller having resilient ends;

Fig. 22 is a perspective view of a modied form of magnetizable pump roller;

Fig. 23 is a fragmentary view of a pump rotor showing an idler roller assisting a conventional roller in a rotor slot;

Fig. 24 is a side view of the idler rotor of Fig. 23;

Fig. 25 is an axial section through a modilied form of pump employing large porting area;

Fig. 26 is a view along the line XXVI-XXVI of Fig. 25 showing an elevation view of the pump porting; and

troduced into the pump, whereupon the pump is actuated by a drive shaft, such as shaft 22 shown in dotted outline. The output from the pump is delivered through. an integrally formed boss 23, the flow being indicated by appropriate arrows.

Referring now to all of Figs. l through 5, it will be noted that the pump housing 2e is formed with a circular cylindrical interior 2t in which is disposed an inner end plate assembly 2e, a rotor member 2l, a cavity ring 28, an outer end plate z' 2S and a retaining ring si locking all of the members together within the housing 2i). The rotor Zi is axiallv relieved at into which iits a projection 3d oi the face plate 2S, which projection acts as a bearing for the rotor E'i in aligni ment with the radial thrusts exerted on the rotor by the pumped fluids.

It will be noted, particularly with reference to Fig. 4, that there is provided variable capacity members 32 in each end of the cavity ring 2s for .Y

varying the displacement of the pump, and these members will be described in more detail hereinafter, particularly with reference to Fig. lil.

Also secured within the cavity ring 28 are arc blocks 33, which are accurately machined to form fa leak-proof seal between adjacent pressure and intake areas of the pump, the radially curved face bearing against the rotor, spring loaded as shown in Fig. 19, if desired, to maintain seal, the back divided into two or more (three shown) sections, each section independently ported, as indicated at 33a, 33h and to the adjacent section of the rotor face, so the pressure urging it against the rotor is slightly greater than the uid pressure of the adjacent areas of the rotor, either by reason of the spring load or because any leakage or" pressure will he on the rotor side of the blocks.

The rotor 2li has peripheral grooves 3s formed therein which are parallel to the axis of rotation, and in which rollers are loosely retained.

The various components of the assembly shown in Figs. l through 5 are illustrated more clearly in Figs. 6 through i3. rlhe porting within the pump housing 2li is shown in part in Fig. 6, the other half of the porting being in the section that is removed from that figure, and is illustrated in Fig. e. Shown in Fig. d, however, is a recessed portion 3'! in the intermediate portion of the cylindrical icavity 2li forming one of two identical portions of the iiuid inlet inaniold. In the lower part of Fig. 6 is shown a similar cavity 3d which is one of two identical parts of the fluid outlet manifolds, the recess 35 being connected by cast passageways St within the housing 2i? to an outlet formed in the integral boss 23 to which any desired conduit may be attached.

The initial portion of the iiuid inlet manifold is shown in Fig. 7, wherein it will be noted that the outer end plate 2d has integrally `formed therein, preferably by casting, passageways ii which also appear in dotted outline in Fig. 2. The inlet manifolding is continued within the cavity ring 2S.

The cavity ring 28 is best illustrated in Figs.

3 and 9, wherein it will be noted that there are four radial slots formed therein, two opposed slots i2 acting as terminal portions of the inlet manfold and the two other opposed slots 43 acting as initial portions of the outlet manifold. Further with reference to Figs. 8 and 9, it will be noted that the cavity ring 2s has external shoulders formed on the interior thereof near the various ports as indicated at lis. These shoulders 64 form the portions upon which the spider assembly 32 (Fig. i0) rests, and rectangular relieved portions 45 in the spider ring accommodate the enlarged base of the spider 32. The rollers 3E, however, normally contact curved interior portions d5 of the cavity ring 23.

Thus, by reference to Figs. 7, 8 and 9, it will be apparent that the inlet to the pump includes the passageways il in the outer end plate 29, the relieved portions 3i in the pump housing 2t and the slotted passages i2 in the cavity ring 28.

The outlet manifold connections on the other hand are best shown with reference to Figs. 5 and 6, fluid fiowing through the slots 43 in the cavity ring 28, thence into the relieved portions 38 on the interior or" the pump housing 2i), and through the passageways se to the outlet boss 23.

As mentioned previously, my invention includes improved means for varying the working cavity volume of the pump, and this function is performed by the two spiders 32 shown best in Fig. 10. .in that figure it will be seen that there is a `solid rectangular base il having a groove it formed about the perimeter thereof and adapted to receive a sealing ring 51 best shown in Fig. 3. Projecting from the rectangular base 4i along the two opposite edges are curved legs 5i of rectangular cross-section that are adapted to rest in the shoulders #is formed in the cavity ring 28, as previously described. The rectangular base il of the spider 32 i'lts within the rectangular recesses il@ of the ring 28 which has been described previously with reference to Fig. 8.

lt will be noted from an inspection of Figs. 3 and 5 that the interior end plate 2S has fitted therein a separate plate 52 formed particularly in accordance with my invention. The end plate it is shown best in Fig. 1l wherein it will be observed that the interior of one face is recessed in oblong fashion at 53 with deeper recesses 54 formed from the approximate position of the minor axis to the approximate position of the major axis, including sufficient area to be equal or greater than the adjacent pressure area of the rotor. The recessing operation leaves an internal hangs 5t. The adjustable member 52 fitting within the inner end plate 25 is shown in Fig. 12 and there it will be noted that this member has two raised portions El of a size and shape corresponding to the two relieved portions 5ft of greatest depth of the member 26 of Fig. l1. Further, these raised portions 5l are provided with perimetric grooves 55 adapted to receive a sealing ring 5e best shown in Figs. 3 and 5. The member 53 is drilled through the two raised portions El as at 53, allowing uid under pressure to act equally on both sides of the raised portions 51. The assembly of the two pieces of Figs. 1l and 12 is indicated in Figs. 3 and 5 and is performed by rotating the member of Fig. l2 about a vertical axis so that the two raised portions 5T are oppoto the more deeply re essed portions 54 of Fig. ll and the two are then pressed together forming the end plate assembly together with the sealing ring q5S.

Referring now to general featuresl of design,

particularly with reference to Fig. 4, it will be noted that the curved interior portions 45 of the cavity ring 28 make a smooth contact with the arc block inserts 33. This contact is of special design in accordance with my invention and embodies the use of a parabolic or a semi-elliptical or other smooth curve that is initially tangent to the true circle of the arc blocks 33, and all parts of the curve lie on or inside of all tangents to the curve between the junctions of the arcs of the blocks 33 and the curve between them. This permits a true circular pressure seal at the blocks 33 Without an angular break in contour such that would cause the rollers or vanes to jump, vibrate or pound such as is present in other pumps. In

this connection, it should be noted also that the arc blocks 33 may be formed with extreme accuracy and appropriately hardened and thereafter inserted in the cavity ring 28, thus facilitating construction of this part of the pump rotor 27 has its shaft portion 62 sealed withinv the housing 2B by a sealing means G3. In connection with all the seals illustrated, it should be noted that these may be of the type commonly employed in hydraulic equipment wherein the annular seal has a circular cross-section, the diameter of which in its free condition is slightly in excess of its groove depth in which it is placed, resulting in an initial compression when assembled. When liquid thereafter conta-cts these seals, they are further compressed against one edge of the groove, this fluid pressure still more effectively causing the ring to seal against leakage- Further with reference to Figs. 3 and e, it will be noted that the pump housing 2t is drilled at 64, which drill hole communicates with a similar hole 65 in the cavity ring in the region of the rectangular recess llt. These two holes permit the use of a mechanical actuator to urge the spider 32 toward the rotor or, alternatively, to admit fluid pressure which urges the spider 32 toward the rotor. This fluid under pressure may be obtained by tapping the output of the pump, as indicated by the conduit 55 as shown in dotted outline in Fig. 3.

Further with reference to Figs. 3 and 5, it will A be noted that the rollers 33 are centrally recessed at each end as at 35. This eliminates the rounded wear of rollers which is otherwise encountered and thereby 'eliminates the tendency of such a rounded roller to bind in the pump cavity or to leak about its rounded end. The wear on the ends of the rollers approximates a lapping action, and it is well known that a ring will lap fiat or planar, whereas the end of a cylinder laps to a convex surface.

The operation will be described with reference to Figs. 1 through 5. Power is applied by the shaft 22 splined onto the rotor stub shaft $2, causing the rotor 2l as a whole to rotate, for example, in the direction of the arrow indicated in Fig. 4. Fluid then flows from the conduit 2l into the interior of the end plate 2S to passages itl (Fig, 2), and thence into recesses 3i (Fig. li), through the cavity ring slots 42 as shown in dotted outline in Fig. 4i. The rollers 36 are thrown outwardly by centrifugal force and are rolled on the inner circular edges 33 of the cavity ring 28. As the rollers leave the arc block plates 33, the volume between two successive rollers gradually increases, reaching a maximum at the end portions of the oval-shaped cavity, at which point the rollers are contacting the central solid portion of the spider 32. Thus, during this travel from the arc blocks 33 to the central spider portion 32, fluid is being induced into the rotor region by suction and is carried across the solid portion of the spider 32. Thereafter, when the rotation is from the center of the spider 32 to the arc blocks 33, the cavities between successive rollers gradually decrease, thereby expelling liquid or fluid from the rotor region and driving it outwardly to form the high pressure output of the pump. Thus, the duid is driven outwardly through the slots 43 in the cavity ring 23 into the relieved portion 33 of the housing 2i), and thence through the passages 32 to the outlet boss 23.

The contact with the arc blocks 33 is extremely exact due to the close machining of the insert 33 and the Contact of the cavity ring surfaces 45 With the arc blocks 33 is smooth, being tangential to the terminal edge of the are block 33. The contact of the rollers with the surface 45 and 'the arc blocks 33 is rolling, reducing friction and wear to a minimum on these rolling Contact surfaces, thus increasing efficiency and life of the pump as a whole.

When it is desired to vary the output of either or both cavities of the pump, a mechanical operator or hydraulic nuid under pressure is admitted to the passage Ed in the housing 2t and in passing through the cavity ring hole 65 acts on the outer end of the spider 32, forcing it inwardly, This reduces the allowable maximum of the cavities formed between successive rollers and thus reduces the output oi the pump for a given rotational speed.

Referring particularly to Fig. 5, it will be noted that the inner end plate 2S retains the movable member 52 having the drilled passage 5t communicating the high pressure regionof the pump (as indicated by the output connection) with the interior or right-hand face of the insert 52. Thus, the pressure of the pump is transmitted to the back of the plate 52, causing it to neat, and by making the area of the plate 32 slightly in excess of the working area of the output cavities of the pump, a slight force can be exerted by the plate 52 toward the rotor and its rollers, thus maintaining an automatically adjustable conipression contact with the rotor, reducing leakage. If desired, light springs may be interposed behind plate 52 to maintain the seal when the pump is at rest.

Various modifications of the rollers 36 of the invention are shown in Figs. 14, 15 and 16. Fig. 14 illustrates a roller having a metal core 6l coated with a rubber-like material, such as neoprene, and is particularly useful in pumps that handle gritty substances that cause pitting of the metal rollers.

Fig. 15 shows a metal roller having a central portion GQ with rounded ends on which are disand thus eliminate voids in the rotor as it passes the arc blocks 33, making this structure particularly adaptable for pumping gases, though for pumping liquids, it may be desirable to relieve the slots as is later described with reference to Fig. 27. Further, with reference to Fig. 16, it will be noted that the outer surface 'it of the vanes is curved so as to conform closely to the radius of the rotor surface, but to clear a cavity surface, insuring the contact line will be the roller itself, thus facilitating the close contact of the vane element with stator walls, further reducing any .l

voids that might be present.

Fig. i7 illustrates an application of my variable capacity pump for use as a fluid mixer. This is based upon the fact that the vane pumps are positive dispiacement pumps and when two or more separate outputs are joined in one conduit, mixing in exact ratios or proportions is obtained. In that figure is illustrated a pump casing 'l5 in which are placed two variable cavity members 'it having stems il that project radially outward through the casing. inlet pipes it and le introduce the two diiferent fluids to the pump casing 'i5 and when the pump is actuated (rotating parts are not shown), uid is delivered to 'two outlet pipes Si 82 joined together at et where they are mixed in the exact proportions desired. The two variable cavity members le are operated independently or together by means of lever arms 83 pin jointed to ears .2L- integrally formed on the casing l5. are pin jointed to internally threaded collars 85 having a common threaded shaft Se passing therethrough. Secured to a center part of the shait S is an annulus 8l engaged by two bushing nuts i threaded into a :fired member $353 secured to the pump casing it. rlhus, the shaft tt as a whole may be moved one way or the other to change the settings of the two variable members le and in addition the shaft S5 may be manually rotated as by the link Sil to change the proportions of the iluids. By selecting the pitch of the threads for each end of shaft 8%, either alike or diiferent, any combination of uniform or diiferential adjustment of the two cavities may be obtained.

Illustrated in Fig. 18 is a modincation of my pump structure wherein the cavity ring is rotatable vvithin limits instead oi i'lXed. A pump casing Si has inlets and outlets indicated by the arrows for direction of flow and has placed within its circular interior a cavity ring 532 of corresponding circular outside shape. A pin 93 is secured to the cavity ring e2 and engages a stop pin 94 near an outlet port and the cavity B2 `as a whole may be rotated counter-clockwise 90 to engage a second stop pin 95. It will be noted that this 96 rotation will shift the delivery ports of the cavity ring 96 with respect to the fixed pump casing si. Therefore, when the direction of rotation or" a rotor (not shown) is changed, the frictional engagement of the rotor with the cavity ring Q2 will cause it to rotate in the new direction of travel, thus shifting the ports. Due to the tact that a change of rotation of travel reverses the flow of uid through the ports, the rotation of the cavity ring corrects for this reversal, causing the new flow to be delivered out i the same ports as the prior ow. Thus, is obtained a uniform direction of flow through the pump casing regardless of the direction of rotation of the rotor. rlhis mechanism is particularly useful on lathes, rolling mills, etc. wherein the pump may be used as a lubrication pump driven by the main machinery which is being frequently The outer ends of the lever arms 83 reversed in direction, while the lubrication flow and direction remain constant.

On the other hand, the direction of iiuid delivery may be reversed without reversing the direction of rotation of the rotor by positively moving the stator between its limits of motion by means of any suitable moving device diagrammatically indicated in Fig. 8 as a handle S.

Provision of the movable end plate 52 described particularly with reference to Figs. 1l and 12 is also used as a means for compensating for wear of the rotor face and the roller ends, as well as providing a seal that is proportional to the working pressure. As the adjustable end plate 52 moves toward the rotor to compensate for wear in the rotor, it would tend to interfere with the spider section 32 and the arc block sections 33. In this connection it will be noted that except for the guide surfaces Q5, the legs 5i of the spider member 32 and the edges of the arc blocks 33 form substantially the entire peripheral edge portions of the entire cavity in which the rotor 2l operates. Accordingly l provide means for allowing the movable end plate e2 to move toward the spiders 32 and the arc blocks 33 in the form of interlocking grooves.

lShown particularly in Fig. 12 are milled notches el on the outer edge of the adjustable end plate 52, which edge will contact the spider 32 and the arc blocks 33 when the entire end plate 52 is rotated to t 'within the stationary end plate 25 of Fig. l1 as previously explained. Likewise, the spider members 32 have their'legs `5i adjacent to the end plate 52 notched at Se as shown in Figs. l0 and 2Q. These notches 98 are preferably made with milling cuts and are parallel to the direction of movement of the entire spider 32. The notches t leave raised portions a between them, which raised portions 98d are so positioned with respect to the end plate 52 that they are positioned opposite the grooves Si of the end plate 52, the grooves il being cut parallel to the notches 93. The arc block members 33 likewise have milled notches 99 formed parallel to their direction of movement and the raised portions 99a between the notches match corresponding grooves Si in the end plate 52. Therefore, when wear occurs on the axially transverse face of the rotor 21 and on the ends of the rollers 3B, the pressure biased end plate 52 may move toward the rotor 2 without hindrance since the notches previously mentioned are complementary and interlock. This construction of notches therefore permits the end plate .52 to not only maintain a :pressure responsive sealing engagement with the rotor, but also permits it to compensate for wear. The notches are preferably much smaller than the width of the webs between the rotor slots and may be about half as wide as the dia-meter of the rollers. In connection with Fig. 19 the arc blocks 33 may be urged toward the rotor 2? by means of a spring 38a.

Shown in Fig. .2l is a Inodied form of pump roller lill having projecting pegs l il?. on each end. Bonded to each end and covering the pegs i532 is a cap H33 of rubberdike material such as neoprene. This structure results in the entire end portions of the roller being resilient and there is little tendency for the end cap m3 to wear ii the roller lill gets out of axial alignment with the rotor. Also in the pumping of gritty substances, the particles which would normally cause a wearing action tend to depress the rubber momentarily and roll along its surface until the particle is clear of the roller. Thus instead of a grinding action which induces wear, a rolling relatively non- 9 wearing action isproduced at the ends of the roller.` l s Shown in Fig.v 22 is a roller |05 made ci man!" netically permeable material such as hard steel or steel metal alloys and made into a simple permanent magnet. When this roller its is used in connection with a ferrous cavity ring 28 and a non-ferrous rotor 2l, it clings to the cavity ring 28. The cavity ring may be magnetized and the roller made of magnetizable material to accomplish the same result. This roller is therefore highly desirable for pumps operated at very low rotational speeds or pumps `that must have a positive displacement upon initial rotation without any 'lost output. IThis type of roller is also highly desirable in adapting the construction for use as a iiuid motor.

Shown in Figs. 23 and 24 is a rotor construee tion employingan idler roller to insure that the main roller will be thrust outwardly. A rotor segment 68 hasran axial peripheral groove lill therein inwhichis placedY a solid cylindricalinain roller i and a'smaller idler roller H39 having its central portion relieved. When the rotor lil-'5 moves in the Vdirection of its arrow, the main roller |03 will contact the inner edge of the arc cavity (not shown)- and rotate in the direction indicated by its arrow. The main roller iiiii contacting the idler roller iii@ will cause the idler roller lil to rotate'in the direction of its'arrow causing the idler roller Iii to tend to climb out of the groove li. This action tends to push the roller Hi8 outwardly and into very secure engagement with an' arc cavity in `which it is used. his arrangement of rollers is very desirable with extremely viscous fluids.

Shown in Figs. 25,26and 27 in a modiiied form of the invention wherein an extremely large porting area is obtained relative to the pumping volume. A pump casing is for-med of two portions, a rear portion ii l and a front portion H2. The front portion H2 has an inlet opening H3 and an outlet opening i ifi. Positioned within the housing parts is a Vrotor i l having a bearing within the rear housing 'portion iii. The inlet and outlet ports are symmetrical and introduce and receive liquid or iiuid at four separate :points to the rotor i i; namely, at the outer periphery, at the ends of the rollers, at the edges of the rotor, and at the bottom of the rotor slots. The left half H2 of the housing is shown in Fig. 26 and it will be noted that the four inlet portions include an outer opening i il and concentric semi-circular slots H8, iid and 52e. rIhe outlet has corresponding slots 22, 23, |25.. and the main outlet opening ld, all corresponding to the four porting areas mentioned previously. A common manifold |27 connects the four inlet areas and a common manifold connects the four outlet areas. The rear housing portion iii is similarly formed.

Referring to Figs. 25 and 27, it will be noted that the rotor construction includes axial peripheral slots |29 in which are disposed rollers |3|. Further, the forward or left portion of the rotor |li contains a plurality of axial recesses |32 near the axis of the rotor each communicating with the center portion of the roller slot |29 by means of a radial passage |33. The bottoms of the slots |29 toward each rotor face are angularly recessed yas at |34. The innermost semi-circular inlet port Y|20 supplies fluid to the passages |32 and |33 which supply fluid to the center portion Yof the slot |29. The intermediate port Il@ supplies uid to the tapered portions i3d of the slot supplying fluid to the slot at the edges. The outermost semi-circular port H8 supplies fluid CII l to the slots |29 at the ends of the rollers |3| and the main inlet port supplies uid peripherally to the rotor.

By means of the large porting area shown in Figs. 25, 26 and 27, my pump is enabled to operate at extremely high speeds without cavitation. Further, it permits the use of a roller-type vane pump for extremely viscous iluids such Vas liquid asphalt which have heretofore been beyond the capabilities of vane-type pumps.

I prefer to use roller-type vanes in my pumps because they eliminate pulsations in the output of the pump as compared to normal vane pumps. This is due to the fact that in normal vane pumps, the vane represents a dead volume which results in the non-uniformity of fluid output. In the roller-type vane, however, as the roller is depressed down within its groove, it displaces liquid from this groove, ejecting it into the outlet of the pump and thereby maintaining the outlet delivery uniform. This lack of pulsation and general smoothness of operation of pumps made according to my invention permit the use of extremely high speed pumps that can operate satisfactorily on speeds in the range of 40,000 to 50,000 R. P. M. These high rotational speeds are especially desirable in association with turbine type equipment such as exhaust gas supercharger turbines or the conventional hot air or jet turbines, allowing direct coupling of the fuel pumps, lubrication pumps, etc. to the main shaft.

While I have described by invention with reference to particular embodiments thereof, it is evident that the invention is equally applicable to other types of pumps; for example, I have shown dual cavtypumpa but the invention disclosed herein is equally applicable to single cavity or any other numbered cavity pumps. Also, I have shown my invention as applied to a single cavity pump, but it is readily apparent to those skilled in the art that the invention is applicable to pumps of any number of cavities. Likewise, the invention may be usefully employed in a iiuid motor and is not therefore restricted to pumps.

It will be noted also with respect to Fig. 4 that the slots 34 of the rotor 2l have non-parallel sides and further are flared outwardly in excess of a'radial direction. These angular side Walls make it impossible to jam the roller in the slot and the pump is very tolerant of dirt and other foreign matter. The outward nare in excess of a radial direction also tends to urge the rollers more securely in contact with the cavity Wall. Additionally, the slot is much easier to machine than one with parallel walls because it may be easily milled or hobhed on standard gear cutting equipment.

While I have described what is at present considered to be the preferred embodiments of my invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of my invention.

iY claim:

l. In a pump, a housing having a circular cylindrical cavity open at one end and having a concentric smaller aperture at the other, a circular rotor disposed within the housing having a shaft on one side concentric to the cavity and projecting through the aperture for a driving connection, said rotor having a cylindrical cavity on the other side concentric to the cavity in the housing, a circular end plate closing the open end of the cylindrical cavity of the housing and having Ian integral concentric projection on the inner surface thereof which fits within the rotor cavity to act as a bearing for the rotor, the end plate being free of any shaft aperture, and loclz. means for securing the end plate to the housing.

2. In a pump, a housing having a circular cylindrical cavity open at one end and having a concentric smaller aperture in the other, a gen erally circular cup shaped rotor disposed therein having a shaft on one side projecting `through the aperture for a driving connection and having a cavity in the other side concentric to the housing cavity, a circular end plate tting in the housing cavity and having an integral projection on the inner side thereof which ts Within the rotor cavity to act as a bearing, the end plate being free of any shaft aperture, said end plate having a central recess on the outer side thereof, and lock means for securing the end plate in the housing.

JOHN STEWART WILCOX.

REFERENCES CEEED The following references are of record in the file of this patent:

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